车辆荷载作用下大跨径预应力矮塔斜拉桥的疲劳分析及寿命评估

发布时间：2018-05-10 04:55

本文选题：标准疲劳车 + S-N曲线　；参考：《大连海事大学》2014年硕士论文

【摘要】：论文基于有限元软件ANSYS对辽宁省大连市长山大桥进行车辆荷载作用下的结构疲劳分析及寿命评估,长山大桥是国内东北地区首座跨海预应力矮塔斜拉桥。首先对国内外矮塔斜拉桥的发展概况以及疲劳分析进展作了对比和总结。从桥梁结构上来讲,部分斜拉桥不同于普通斜拉桥,部分斜拉桥的斜拉索实质上起着体外预应力索的作用,是一种刚柔并济的桥型,国内外越来越多矮塔斜拉桥的出现为桥梁的发展提供了更为广阔的空间。近年来,桥梁因疲劳破坏而造成的事故层出不穷,结构的疲劳问题也逐渐成为国内外学者研究的重点。疲劳车辆载荷谱的确定是研究车载下桥梁疲劳特性的关键,确定方法主要有规范法、调查法和实测法。英国的BS5400新疲劳设计规范、美国AASHTO公路桥梁设计规范以及欧洲钢结构疲劳设计规范中对标准疲劳车均有规定,本文由于长山大桥尚未通车,这里将采用美国标准疲劳模型车来进行加载。根据结构静力分析确定疲劳“热点”,这里主要对桥梁结构的斜拉索、主梁跨中、塔梁墩固结处、边跨跨中以及中跨跨中部分进行了结构疲劳分析,结构的疲劳取决于反复荷载作用下节点的应力幅值。对于斜拉索来讲,找出行车荷载下应力幅最大的拉索,并根据该拉索的S-N曲线以及疲劳损伤准则对该拉索进行寿命评估,论文还分析了各拉索在行车荷载作用下的应力变化规律；对于钢筋混凝土梁段,绘制主梁梁段疲劳“热点”处的影响线以寻找出该“热点”的最不利荷载位置,然后结合钢筋混凝土梁的疲劳特性并利用疲劳分析软件FE-SAFE对其寿命进行评估。根据以上分析结果,对矮塔斜拉桥的疲劳分析方法进行了总结,为斜拉桥的疲劳分析及寿命评估提供了一些依据。
[Abstract]:Based on the finite element software ANSYS, the structural fatigue analysis and life evaluation of Changshan Bridge in Dalian City, Liaoning Province, under vehicle load are carried out. Changshan Bridge is the first cable stayed bridge in Northeast China. Firstly, the development and fatigue analysis of the cable-stayed bridge with low tower at home and abroad are compared and summarized. In terms of bridge structure, partial cable-stayed bridge is different from ordinary cable-stayed bridge. The emergence of more and more cable-stayed bridges with short towers at home and abroad provides a broader space for the development of bridges. In recent years, the accidents caused by fatigue damage of bridges have emerged one after another, and fatigue problems of structures have gradually become the focus of domestic and foreign scholars. The determination of fatigue vehicle load spectrum is the key to study the fatigue characteristics of bridge under vehicle. The determination methods mainly include normative method, investigation method and actual measurement method. The new fatigue design code of BS5400 in Britain, the design code of AASHTO highway bridge in the United States and the fatigue design code of steel structure in Europe are all stipulated in the standard fatigue vehicle. In this paper, the Changshan Bridge has not been opened to traffic. An American standard fatigue model car will be used here for loading. According to the static analysis of the structure, the fatigue "hot spot" is determined. In this paper, the structural fatigue analysis is mainly carried out for the stayed cables of the bridge structure, the middle span of the main beam, the consolidation place of the pier of the tower beam, the middle part of the side span and the middle part of the middle span. The fatigue of the structure depends on the stress amplitude of the joints under repeated loads. For cable-stayed cables, the cable with the largest stress amplitude under driving load is found, and the life of the cable is evaluated according to the S-N curve of the cable and the fatigue damage criterion. The paper also analyzes the stress variation law of each cable under traffic load, for the reinforced concrete beam section, draws the influence line at the fatigue "hot spot" of the main beam section to find out the most unfavorable load position of the "hot spot". Then the fatigue characteristics of reinforced concrete beams and the fatigue analysis software FE-SAFE are used to evaluate the fatigue life of reinforced concrete beams. Based on the above analysis results, the fatigue analysis method of cable-stayed bridge with low tower is summarized, which provides some basis for fatigue analysis and life evaluation of cable-stayed bridge.
【学位授予单位】：大连海事大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U448.27;U441.4

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